JP2021066285A - Underwater control system for construction machine - Google Patents

Abstract

To provide an underwater control system for a construction machine capable of securing communication stability when controlling a construction machine for carrying out work underwater by using radio communication technology.SOLUTION: An underwater control system for a construction machine for controlling the construction machine carrying out work underwater by using underwater sound communication includes a command information dispatching device for dispatching command information to the construction machine as sound waves and a machine controller for receiving command information dispatched as sound waves from the command information dispatching device and controlling the construction machine based on the command information. The machine controller is included in the construction machine.SELECTED DRAWING: Figure 2

Description

The present invention relates to an underwater control system for a construction machine for controlling a construction machine that operates underwater.

Conventionally, in marine construction and revetment construction, it has been an issue to ensure the workability and safety of divers who work underwater. For example, in Patent Document 1, a machine in which a diver performs construction work underwater is used. An underwater work support system that provides support when operating is disclosed.

Specifically, while a visible light receiver is provided in a machine that works underwater, a visible light transmitter is provided in the underwater worker's equipment equipped by the underwater worker, and the operation of the machine by the underwater worker is performed by the underwater visible light. It is carried out by communication. As a result, underwater workers can secure a sufficient distance from the machine, which can reduce accidents such as contact with the machine, pinching accidents, and accidents involving the machine such as being entangled in wiring. it can.

Japanese Unexamined Patent Publication No. 2016-78791

However, in the operation of a machine by underwater visible light communication, the communication status tends to depend on the turbidity in water and the like, and when the water is turbid, the communicable distance becomes significantly short. In order to perform the work under such a situation, the underwater worker has to approach the machine and operate it, which makes it difficult to ensure the safety of the underwater worker.

The present invention has been made in view of such a problem, and a main object thereof is to be able to secure communication stability when controlling a construction machine working underwater by using wireless communication technology. , To provide an underwater control system for construction machinery.

In order to achieve such an object, the underwater control system for a construction machine of the present invention is an underwater control system for a construction machine for controlling a construction machine working underwater by using underwater acoustic communication. A command information transmitting device that transmits command information to a machine as a sound wave, and a machine control device that receives the command information transmitted as a sound wave from the command information transmitting device and controls the construction machine based on the command information. , The machine control device is equipped with the construction machine.

According to the underwater control system of the construction machine of the present invention, since the underwater acoustic communication is used as the wireless communication technology, the construction machine can be stabilized even at the work site in various water environments without depending on the water quality and the like. Can be controlled. Therefore, for example, even in highly turbid water, an underwater worker such as a diver can safely control a construction machine working underwater while maintaining a certain distance from the construction machine. Become.

Further, the underwater control system for construction machinery of the present invention is characterized in that the frequency band of the sound wave is set within a range of 100 Hz or more and 20 kHz or less.

According to the underwater control system of the construction machine of the present invention, when using the underwater acoustic communication, the carrier frequency band of the carrier wave that carries the command information of the construction machine is set within the audible range within the range of 100 Hz or more and 20 kHz or less. To do. This occurs between the transmitter and the receiver, which is generally referred to as Doppler shift, as compared to the case of using ultrasonic waves exceeding the audible range of about 30 to 40 kHz used in underwater acoustic communication. Minimize the effects even in an aquatic environment where the frequency band changes due to relative speed differences and the phenomenon called multipath fading, in which the reception intensity of sound waves fluctuates, is likely to occur. This makes it possible to improve the stability of underwater acoustic communication.

Further, since the command information transmitting device can perform underwater acoustic communication with the machine control device provided in the construction machine by arranging at least a transmitter that transmits the command information underwater, the field worker can perform the underwater acoustic communication. , Command information for controlling construction machinery can be input to the command information transmission device while on board or on land, even if it is not underwater. Therefore, it is possible to improve the workability and safety of field workers by reducing the diving work time by underwater workers such as divers or by reducing the labor of underwater workers.

The underwater control system for construction machinery of the present invention is characterized in that a plurality of the sound waves are set at different frequency bands, and the command information is transmitted by the plurality of the sound waves.

According to the underwater control system of the construction machine of the present invention, the same command information is transmitted by each of a plurality of carriers having different carrier frequency bands. Therefore, when receiving the information, various methods such as the above-mentioned Doppler shift and multipath fading are performed. It is possible to select and receive the one with the least influence of the phenomenon or underwater noise, obtain the command information, further improve the communication stability, and control the construction machine reliably.

The underwater control system for construction machinery of the present invention is characterized in that the command information transmitting device is provided with a noise detection unit for detecting underwater noise.

According to the underwater control system of the construction machine of the present invention, based on the frequency information of the underwater noise detected by the noise detection unit, the one belonging to the frequency band that does not correspond to any of the frequency components of the underwater noise or its harmonics is selected. Can be selected as a carrier wave. Therefore, among various underwater noises that hinder underwater acoustic communication, at least the possibility of causing communication failure due to the acquisition of frequency information can be eliminated, and the stability of underwater acoustic communication can be further improved. Is possible.

According to the present invention, since underwater acoustic communication using a carrier wave whose carrier frequency band is set within the range of 100 Hz or more and 20 kHz or less is used, the stability of underwater acoustic communication even at work sites in various water environments. It is possible to safely control construction machinery that works underwater.

It is a figure which shows the state of controlling the underwater suspension swivel device by using the underwater control system in embodiment of this invention. It is a figure which shows the outline of the underwater control system of the construction machine in embodiment of this invention. It is a figure which shows the case where a plurality of carrier waves are used for carrying command information in embodiment of this invention. It is a figure which shows the flow at the time of transmitting the command information in embodiment of this invention. It is a figure which shows the relationship between the communication distance and the attenuation amount of the reception level in the underwater control system in embodiment of this invention. It is a figure which shows the other example at the time of controlling the underwater suspension swivel device by using the underwater control system in embodiment of this invention.

The underwater control system of the present invention can be adopted in any water environment such as the ocean, rivers, lakes and marshes, but in the present embodiment, the case where it is adopted in the ocean is taken as an example, and the underwater control system for construction machinery is used. Details will be described with reference to FIGS. 1 to 6.

Further, the construction machine that works underwater is not limited in any way, but in the present embodiment, the underwater suspension swivel device is adopted, and the underwater suspension swivel device is used in the underwater civil engineering work. An example is given when the installation work of a concrete block, which is one of the above, is carried out.

As shown in FIG. 1, the concrete block B to be installed on the seabed is suspended underwater by a crane 61 mounted on a hoisting vessel 60 via an underwater suspension swivel device 50.

When installing a concrete block B such as a tetrapod or a rooting block on the seabed, the underwater suspension swivel device 50 controls the posture of the suspended concrete block B such as changing the direction and maintaining the posture by turning, and This is a device for making fine adjustments during positioning underwater. For the principle of attitude control by the underwater suspension swivel device 50, refer to Japanese Patent No. 5970946.

The above-mentioned underwater suspension swivel device 50 has a shackle 52 for mounting a wire 62 suspended from a crane 61 of a hoisting vessel 60 on the upper surface of the outer shell 51, and a concrete block B on the lower surface of the outer shell 51. A hanging jig 53 for suspending the crane 53 is provided. As a result, the underwater suspension swivel device 50 is suspended in water via the wire 62 attached to the shackle 52 while the concrete block B is suspended by the suspension jig 53.

When installing the concrete block B on the seabed, the concrete block B is suspended underwater while checking the position and posture of the concrete block B visually by an underwater worker D such as a diver or by a monitoring camera or the like deployed in the sea. By turning the load swivel device 50, posture control such as changing the direction of the concrete block B is performed.

In this way, after fine-tuning the attitude control and positioning of the concrete block B, the operator of the crane 61 pays out the wire 62 to lower the underwater suspension swivel device 50 and the concrete block B, and sets the concrete block B on the seabed. wear.

In such installation work of the concrete block B by underwater work, the underwater suspension swivel device 50 is controlled by the underwater worker D such as a diver or the water worker S who is on board the crane vessel 60. It is performed by underwater acoustic communication using.

Below, as shown in FIG. 1, the case where the field worker who operates the underwater suspension swivel device 50 is the water worker S who is on board the crane vessel 60 is taken as an example, and the details of the underwater control system 100 are described. explain.

≪Underwater control system≫
As shown in FIGS. 1 and 2, the underwater control system 100 receives the command information transmitting device 10 in which the water worker S transmits the command information M to the underwater suspension swivel device 50 as sound waves, and the sound waves. A mechanical control device 20 for controlling the underwater suspension swivel device 50 based on the command information M is provided.

<Command information transmitter>
As shown in FIG. 2, the command information transmitting device 10 includes a command input unit 11, an oscillator unit 12, a carrier wave selection unit 13, a modulation unit 14, an amplifier 15, and a transmitter 16. The noise detection unit 19 will be described later.

The command input unit 11 includes an input unit in which the water worker S inputs an operation command of the underwater suspension swivel device 50 in order to control the attitude of the concrete block B. The input unit may be any, but for example, a selection menu related to at least four operation commands such as "clockwise rotation", "counterclockwise rotation", "stop", and "neutral" displayed on the display provided with a display. It is preferable that the water worker S can input the operation command of the underwater suspension swivel device 50 by appropriately performing a selection operation.

Further, the command input unit 11 has a function of converting the operation command input from the input unit into a digital signal, and converts the operation command by the water worker S into the command information M which is a baseband signal, and wirelessly. Output to the connected or wired modulation unit 14.

The oscillation unit 12 creates a plurality of reference waves W to be used as the carrier wave C, and outputs these to the carrier wave selection unit 13 wirelessly or wiredly connected. The details of the plurality of reference waves W will be described later, but as shown in FIG. 3, each of the plurality of reference waves W is created so as to shift the frequency band. When these reference waves W are selected as the carrier wave C, the frequency band of the reference wave W becomes the carrier frequency band of the carrier wave C.

The carrier wave selection unit 13 selects two or more of the plurality of reference waves W to be used as the carrier wave C and outputs them to the modulation unit 14 wirelessly or wiredly connected. In the present embodiment, the number of carrier waves C to be selected is set to two or more in consideration of applying a frequency diversity technique for receiving signals transmitted at a plurality of different frequencies to the reception method.

Therefore, if the number of carrier waves C is a plurality, for example, all of the created reference waves W may be adopted as the carrier waves C. The reception method using the frequency diversity technique will be described together with the machine control device 20.

The modulation unit 14 performs so-called modulation in which the command information M input from the command input unit 11 is mixed with each of the two or more carrier waves C input from the carrier wave selection unit 13, and a plurality of modulated waves having different frequency bands. It forms Mw and outputs it to the wirelessly or wiredly connected amplifier 15. As the modulation method, a BPSK (binary phase shift keying) method that modulates by changing the phase without changing the frequency and amplitude of the carrier wave C is adopted.

With the above configuration, the plurality of modulated waves Mw carrying the same command signal M output from the modulation unit 14 are amplified by the amplifier 15 and then D / A by the transmitter 16 which is a dedicated transducer for transmission. It is converted and transmitted as sound waves into the sea. A plurality of types of sound waves based on each of the plurality of modulated waves Mw may be transmitted with a time difference, or all of them may be combined and transmitted at the same time.

The sound wave transmitted from the transmitter 16 is a D / A-converted modulated wave Mw, and the modulated wave Mw is a carrier wave C modulated by the BPSK method. Therefore, the frequency band thereof is the carrier wave. It has the same frequency band as C.

As shown in FIG. 1, the transmitter 16 may be suspended in water by using the float 63, or may be suspended directly in water from the crane vessel 60. Further, the command input unit 11, the modulation unit 14, the oscillation unit 12, the carrier wave selection unit 13, and the amplifier 15 may be mounted on the crane vessel 60. Further, in the present embodiment, the amplifier 15 and the transmitter 16 are connected by wire, but may be wirelessly connected.

Further, as shown in FIG. 2, the command information transmitting device 10 includes a noise detecting unit 19 for detecting and analyzing the underwater noise N. The noise detection unit 19 includes a noise collecting receiver 17 and a wavelet transform unit 18. Underwater noise N is generated in the sea, such as artificial noise such as ship engine noise and passing noise, and naturally generated noise caused by crustal movements and vortices on the seabed. In underwater wireless communication, it is underwater. Refers to any noise that is treated as noise.

The noise collector 17 employs a dedicated transducer for receiving waves, and as shown in FIG. 1, is suspended in water using a float 63 together with the transmitter 16, or directly from the crane vessel 60. Suspended in the water. As shown in FIG. 2, the noise collector 17 installed in this way collects the underwater noise N, converts it to A / D, and outputs it to the wavelet transform unit 18 connected by wire or wirelessly. To do.

The wavelet transform unit 18 acquires time information (for example, the place where the underwater noise N is generated) and frequency information Nf from the input underwater noise N, and at least the frequency information Nf is connected to the carrier wave selection unit 13 which is wired or wirelessly connected. Output.

Then, the carrier wave selection unit 13 belongs to a frequency band different from any of the underwater noise N acquired from the frequency information Nf or the frequency component of the harmonic among the plurality of reference waves W input from the oscillation unit 12. , The carrier wave C is appropriately selected, and this is output to the modulation unit 14.

As a result, when controlling the underwater suspension swivel device 50 using the underwater control system 100, frequency information Nf can be acquired by at least the noise detection unit 19 among various underwater noise N that hinder underwater acoustic communication. It is possible to eliminate the possibility of causing a communication failure due to the above.

<Machine control device>
On the other hand, as shown in FIG. 1, the machine control device 20 is installed in the outer shell 51 of the underwater suspension swivel device 50, and its configuration is as shown in FIG. 2, the receiver 21 and the frequency diversity unit. A 22, an amplifier 23, a demodulation unit 24, and a control unit 25 are provided.

The receiver 21 is a transducer dedicated to receiving waves that collects various sound waves in the sea and converts them into A / D to obtain an input electrical signal Ms'. In this embodiment, a hydrophone capable of corresponding to an audible range. Is adopted. The sound waves collected by the receiver 21 include various types of sound waves emitted from the transmitter 16 based on the plurality of modulated waves Mw, as well as the various underwater noise N described above.

Further, even if the sound wave is transmitted from the transmitter 16, it is assumed that the sound wave is distorted due to the underwater noise N and various phenomena occurring in the sea. Examples of various phenomena include phenomena called Doppler shift and multipath fading.

The Doppler shift is a sound wave transmitted from the transmitter 16 due to a relative speed difference caused by shaking caused by waves, tidal currents, etc. between the transmitter 16 and the receiver 21 arranged in the sea. This is a phenomenon in which the frequency band of a sound wave changes when it is received by the receiver 21. Further, multipath fading is a phenomenon in which the reception intensity fluctuates when the sound wave transmitted from the transmitter 16 is received by the receiver 21.

That is, the sound wave transmitted from the transmitter 16 is reflected by a structure such as the sea surface, the seabed, or the seawall R, as shown in FIG. 1, in addition to the sound wave that follows a straight path to reach the receiver 21. -There are a plurality of objects that reach the receiver 21 by following a diffracting path. Multipath fading is a phenomenon caused by this, and sound waves that have passed through a plurality of propagation paths interfere with each other, and the reception intensity fluctuates greatly.

Therefore, even if the A / D-converted input electric signal Ms'is demodulated as it is, it is assumed that the command information M cannot be extracted accurately. Therefore, in the present embodiment, the input electric signal Ms'received by the receiver 21 is output to the frequency diversity unit 22 connected by wire or wirelessly.

The frequency diversity unit 22 refers to the carrier frequency band of each of the plurality of carrier waves C selected by the carrier wave selection unit 13 and the harmonics of each carrier wave C (referring to a waveform having a frequency that is an integral multiple of the waveform of the basic frequency). The quality of the input electrical signal Ms'is continuously analyzed using the frequency band. Then, among the input electric signals Ms', the most reliable signal derived from the carrier wave C or its harmonics is extracted as the modulated wave Mw or the processed electric signal Ms corresponding to the harmonics thereof, and is connected by wire or wirelessly. Output to the connected amplifier 23.

Further, in the frequency diversity unit 22, the carrier frequency band of the carrier wave C and the frequency band of the harmonics of the carrier wave C are provided with a width corresponding to the shift amount expected when the Doppler shift occurs, and this is used. Then, the quality of the electric signal Ms is continuously analyzed.

As a result, of the plurality of types of sound waves transmitted from the transmitter 16, one of them is in a collapsed state due to the influence of phenomena such as underwater noise N and multipath fading, or due to Doppler shift. In any case, such as when the frequency band changes, it is possible to acquire the modulated wave Mw or the processed electric signal Ms corresponding to the harmonics thereof from the sound waves received by the receiver 1. ..

The amplifier 23 amplifies the processed electric signal Ms corresponding to the modulated wave Mw or its harmonics, and outputs it to the demodulation unit 24 connected by wire or wirelessly. The demodulation unit 24 demodulates the amplified processed electric signal Ms, acquires the command information M related to the operation command input by the command input unit 11, and outputs the command information M to the control unit 25 connected by wire or wirelessly. .. The control unit 25 controls the operation of the underwater suspension swivel device 50 based on the command information M extracted by the demodulation unit 24.

In this way, the underwater control system 100 uses the underwater acoustic communication technology to transmit the operation command of the water worker S to the underwater suspension swivel device 50 input to the command information transmission device 10 as command information M, and also transmits the operation command to the sea. By receiving this in the machine control device 20, the operation of the underwater suspension swivel device 50 can be controlled based on the command information M.

≪Control method of underwater suspension swivel device using underwater control system≫
A specific procedure for controlling the underwater suspension swivel device 50 using the underwater control system 100 having the above configuration will be described below.

First, a preparatory step to be carried out when controlling the underwater suspension swivel device 50 will be described with reference to FIGS. 2 and 3, but in the present embodiment, eight reference waves W as candidates for the carrier wave C are prepared. Let's take the case of doing so as an example.

As shown in FIG. 3, for example, eight reference waves W (W1, W2, ..., W8) having different frequency bands are created from a predetermined range within the audible range (generally between 20 Hz and 20 kHz). The oscillation unit 12 of the command information transmitting device 10 is set.

In the present embodiment, the frequency band of the reference wave W (W1, W2, ..., W8) used for the carrier wave C which is later modulated by the BPSK method and transmitted as a sound wave, that is, the carrier wave frequency band is audible. It is preferable to create the frequency in the range of 100 Hz or more and 20 kHz or less.

This is because if it exceeds 20 kHz, it tends to be confused with the frequency band used for fish finder and seafloor topography measurement, and if it is below 100 Hz, it takes a long time to transmit data due to the long wavelength. Therefore, it is not only unsuitable for underwater acoustic communication, but also tends to cause damage to the transmitter 16 due to long-term communication, which is also mechanically disadvantageous.

The setting range of the carrier frequency band of the carrier wave C modulated by the BPSK method and transmitted as sound waves is more preferably 500 Hz or more and 10 kHz or less.

If it exceeds 10 kHz, it is easily affected by the Doppler shift described above, and even when the relative speed difference between the transmitter 16 and the receiver 21 is small, the amount of frequency change (shift). Amount) increases. In such a case, the work of extracting the modulated wave Mw or the processed electric signal Ms corresponding to the modulated wave from the input electric signal Ms'of the sound wave collected by the receiver 21 of the machine control device 20 is complicated. It tends to be difficult to ensure the stability of wireless communication in the underwater control system 100.

Further, if it exceeds 10 kHz, the reception intensity fluctuates, which is called multipath fading described above, tends to occur, and the sound wave transmitted from the transmitter 16 tends to be unable to be received by the receiver 21. On the other hand, the frequency band of 100 Hz to 500 Hz is due to the fact that it is easily confused with underwater noise such as engine noise of a ship.

Therefore, in the present embodiment, as shown in FIG. 3, in the oscillation unit 12, the reference wave channelized in a predetermined bandwidth from a particularly suitable range of 500 Hz or more and 10 kHz or less in the range of 100 Hz or more and 20 kHz or less. Eight Ws (W1, W2, ..., W8) are formed. The bandwidth of the reference wave W may be any, but the bandwidth of the carrier frequency band is preferably about 1 to 2 kHz. Therefore, in the present embodiment, as an example, the reference wave W is provided with a bandwidth of 1 kHz. ing.

After the above preparation step is completed, the water worker S transmits the command information M as a sound wave from the command information transmitting device 10 to the machine control device 20. The procedure will be described below according to the flow of FIG.

The water worker S confirms the position and orientation of the concrete block B based on the information acquired from the underwater worker D such as a monitoring camera and a diver deployed in the sea, and the command input unit 11 of the command information transmitting device 10 Is appropriately operated to input an operation command of any one of "right rotation", "left rotation", "stop", and "neutral" to the underwater suspension swivel device 50, and the modulation unit 14 is used as command information M. Output to (Step 1).

At the same time as or before and after the output of the command information M, the noise collecting receiver 17 suspended in the water attempts to detect the underwater noise N (Step 2).

When the underwater noise N is detected, the wavelet transform unit 18 described above acquires the frequency information Nf of the underwater noise N and outputs it to the carrier wave selection unit 13. Then, based on the frequency information Nf, the carrier wave W in the frequency band that does not correspond to the frequency component of the underwater noise N or its harmonics among the reference waves W (W1, W2, ..., W8) is output to the modulation unit 14. (Step 3).

For example, in FIG. 3, among the eight reference waves W (W1, W2, ..., W8) in which the carrier wave selection unit 13 corresponds to the frequency component of the underwater noise N or its harmonics, the reference wave W It is determined that there are five (W2, W4, W6, W7, W8), and the remaining three reference waves W (W1, W3, W5) from which these are removed are used as carrier waves (C1, C2, C3). ), And is output to the modulation unit 14.

On the other hand, when the underwater noise N is not detected, all eight reference waves W (W1, W2, ..., W8) may be output to the modulation unit 14, or a plurality of reference waves W may be arbitrarily selected. It may be (Step 4).

The frequency band of the reference wave W selected as the carrier wave C by the carrier wave selection unit 13 is the carrier wave frequency band. Since the carrier wave C is modulated by the BPSK method that does not change the frequency and transmitted as a sound wave, this information is output not only to the modulation unit 14 but also to the frequency diversity unit 22 of the machine control device 20. deep.

Next, in the modulation unit 14, each of the three carrier waves (c1, c2, c3) is modulated by the BPSK method in order to mix the command information M related to the operation command of the underwater suspension swivel device 50, and the three modulated waves (3 modulated waves). Mw1, Mw2, Mw3) are acquired (Step 5).

After that, each of the three modulated waves Mw (Mw1, Mw2, Mw3) is amplified by the amplifier 15 and D / A converted by the transmitter 16 to obtain a sound wave, which is the receiver 21 of the machine control device 20 located in the sea. Send to. Three types of sound waves based on each of the three modulated waves Mw (Mw1, Mw2, Mw3) are transmitted toward the sea with a time lag, and this is repeated a plurality of times.

In this way, the three types of sound waves transmitted into the sea are A / D converted by the receiver 21 of the machine control device 20 and output to the demodulation unit 24 via the frequency diversity unit 22 as described above. .. Then, the command information M input via the command input unit 11 of the command information transmission device 10 is acquired.

As a result, the control unit 25 controls the underwater suspension swivel device 50 based on the command information M. Therefore, the submersible suspension swivel device 50 corresponds to the operation command of the surface worker S, "clockwise rotation". It is possible to perform any of "counterclockwise rotation", "stop", and "neutral" operations.

The following experiments were conducted on the communication distance when the above-mentioned underwater control system 100 was used. In the experiment, the carrier frequency band of the carrier wave C was set to 1 kHz, the modulation method was set to the BPSK method described above, the output was set to 10 mW, and the receiver 21 of the machine control device 20 was separated from the transmitter 16 of the command information transmitter 10. The amount of attenuation of the reception level was measured at intervals of about 5 m.

Looking at FIG. 5, the attenuation of the reception level that changes as the communication distance increases is gradual, and the attenuation is about 105 db at a point about 38 m away, and the attenuation up to 120 db, which is generally the reception limit, is I couldn't see it. As a result, even if the underwater suspension swivel device 50 on which the machine control device 20 is installed and the transmitter 16 of the command information transmission device 10 are separated by at least about 40 m, the underwater suspension swivel device 100 provides the underwater suspension swivel device. It can be seen that 50 can be controlled.

In the present embodiment, the case where the water worker S controls the underwater suspension swivel device 50 has been given as an example, but the present invention is not necessarily limited to this, and underwater work by a diver or the like who performs work in the sea Member D may control it. In this case, as shown in FIG. 6, the command information transmitting device 10 including the command input unit 11, the oscillation unit 12, the carrier wave selection unit 13, the modulation unit 14, the amplifier 15, and the transmitter 16 is integrated. It is recommended to carry it with the underwater worker D.

As described above, the underwater control system 100 uses the carrier wave C set in the audible range of 100 Hz or more and 20 kHz or less, preferably 500 Hz or more and 10 kHz or less. As a result, even in an environment subject to communication problems such as Doppler shift and multipath fading, compared to the case of using ultrasonic waves far exceeding the audible range of about 30 to 40 kHz used in underwater acoustic communication. The effect can be minimized, and the stability of underwater acoustic communication can be further improved.

In addition, the underwater suspension swivel device 50 can be reliably controlled at work sites in various water environments without depending on the water quality. Therefore, for example, in highly turbid water, even when an underwater worker D such as a diver carrying a command information transmitting device 10 controls the underwater suspension swivel device 50, the underwater worker D and the underwater suspension load It is possible to safely control the underwater suspension swivel device 50 while maintaining a certain distance from the swivel device 50.

Further, the command information transmitting device 10 performs underwater acoustic communication with the machine control device 20 provided in the underwater suspension swivel device 50 if at least the transmitter 16 for transmitting the command information M is arranged underwater. Can be done. Therefore, the field worker can control the underwater suspension swivel device 50 by inputting the operation command of the underwater suspension swivel device 50 from the ship or land to the command information transmitting device 10 even if it is not underwater.

Therefore, it is possible to improve the workability and safety of the on-site worker, such as reducing the diving work time by the underwater worker D such as a diver, or reducing the labor of the underwater worker D.

Further, since the frequency information Nf of the underwater noise N generated at the work site can be acquired by using the noise detection unit 19, the carrier wave C having a carrier frequency band different from that of the underwater noise N is used based on the frequency information Nf. Command information M can be transported. As a result, it is possible to eliminate the possibility of causing a communication failure due to at least the frequency information Nf obtained from the various underwater noise N that interferes with the underwater acoustic communication.

The underwater control system 100 for construction machinery of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in the present embodiment, eight types of reference wave W are selected and three types of carrier wave C are selected from them, but the quantity of both the reference wave W and the carrier wave C is limited to this numerical value. is not it. It is preferable to select a plurality of reference waves W whose center frequencies in the frequency band do not have an integral multiple relationship with each other.

Further, although the noise detection unit 19 is provided in the command information transmission device 10 of the underwater control system 100, the noise detection unit 19 does not necessarily have to be provided.

100 Underwater control system 10 Command information transmitter 11 Command input 12 Oscillator 13 Carrier selection 14 Modulation 15 Amplifier 16 Transmitter 17 Noise collector 18 Wavelet converter 19 Noise detector 20 Machine control 21 Receiver 22 Frequency diversity unit 23 Amplifier 24 Demodulation unit 25 Control unit 50 Underwater suspension swivel device (construction machinery)
51 Outer shell 52 Shackle 53 Hanging jig 60 Lifting machine Ship 61 Crane 62 Wire 63 Floating B Concrete block R Seawall S Water worker D Underwater worker M Command information W Reference wave C Carrier wave Mw Modulated wave Ms' Input electric signal Ms Electrical signal N Underwater noise (underwater noise)
Nf frequency information

Claims (4)

An underwater control system for construction machinery that uses underwater acoustic communication to control construction machinery that works underwater.
A command information transmission device that transmits command information to the construction machine as sound waves,
A machine control device that receives the command information transmitted as sound waves from the command information transmitting device and controls the construction machine based on the command information.
An underwater control system for a construction machine, wherein the machine control device is equipped on the construction machine. The underwater control system for construction machinery according to claim 1.
An underwater control system for construction machinery, wherein the frequency band of the sound wave is set within a range of 100 Hz or more and 20 kHz or less. In the underwater control system according to claim 1 or 2.
A plurality of the sound waves are set with different frequency bands.
An underwater control system for construction machinery, characterized in that the command information is transmitted by a plurality of the sound waves. In the underwater control system according to any one of claims 1 to 3.
An underwater control system for construction machinery, wherein the command information transmitting device is provided with a noise detection unit that detects underwater noise.

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